I also face the same issue. AC crashes or takes for ever when trying to open any item in 'Imported items' tab. AC is installed on the server Windows 2003, Quad core processor with 6GB RAM and two clients (4GB RAM) connected wired with 100MB/s CISCO switch. I am using AC version 6.1.2 (yet not upgraded to 6.3.2, scheduled in the next week).

I also did performance tuning of the server and network.

Sometimes pdf files cannot be opened. I have to right click then open in new window.
Also checked antivirus program Norton that does not interfere with AC.
Thanks for any suggestions.

Orange Pediatrics
Altamonte Springs, FL